A. Field of the Invention
The present invention relates to a new and improved apparatus for rubbing down the spines of case bound books, and to a new and improved method for rubbing down the spines of case bound books.
B. Description Of The Background Art
In assembling case bound books and securing a case to the pages or leaves of the book, extruded glue beads are applied to the spine of the book. If the glue beads are not smoothed out, they can result in ridges and bumps that are visible through the case and results in the case not adhering to the book body. Accordingly, in the process of assembling case bound books, the spine is rubbed to smooth out the ridges and bumps formed by the beads of glue. The rub down process is complicated, however, by the fact that it is preferred that the production speed of book assembly is not slowed down by the rubbing down process. A further complication is that the rubbing down process should be performed in a manner that does not rapidly wear out the equipment.
Rub down processes have been accomplished through the use of spring-loaded pads or stationary mechanisms. Experience has shown that these mechanisms impose an undue force on the case-in wing which reduces the machine life. In addition, these mechanisms subject the books to forces that slide the books on the case-in wings resulting in uneven spreading of the glue, non-uniform glue thickness, and incomplete rubbing of the spine. To correct these disadvantages excess glue must be applied to the spine. The excess glue increases the cost and weight of the books.
There is a need for an apparatus for rubbing down the spines of case bound books that maintains a fixed distance from the case-in wing. Such an apparatus would caliper glue beads to a uniform thickness and coverage across the spines of case bound books, while minimizing the force imposed on the case-in wing carrying the books. In addition, the apparatus would minimize any forces tending to slide the books on the case-in wings. This apparatus would reduce the amount of glue required to obtain full glue coverage and maximize the mechanical bonding across the entire area of each book spine.